Fire control for powder actuated tools



Feb. 2`3\,\l954 R. T. cATLlN FIRE CONTROL FOR POWDER ACTUATD TOOLS Filed Ooi. 24, 1951 Patented Feb. 23, 1954 UNITED STATES PATENT oFFrczE;

QQN'RRQI, AQTUAEDED- Robert' T.' Catlin; Stratford,l Caring assigner to Remington Arms Gompany, Incl, Bridgeport, Conn., a corporationof Delaware Application, Qetcher 2.4,. 1951, Serial. No. 253.249

14 Claim'.

This invention relates to. industrialv` tools ofv the type in which an element is forcefully driven against or into the work by gaspressurederived from the combustion of a propellent-powden and contemplates an improvement in such tools which4v requires, that for operation, the tool be, held in aposition substantially perpendicular tothe face or the work.

More specically, the invention contemplates an improvement in a toolv ofthe type shown in the pending application for United- States patent;`

of Vi'alkerL Serial No. 225,146;Y filed' May 8;' i951;- said improvement providing that'v the firing mechanism remains locked even when the toolv is, pressed against the work; surface unless the tool; isv substantially perpendicular to suchvsurface.

In the drawings:

Fig. l is, a longitudinal sectional view of a, complete tool embodying the presentinvention.

Fig. 2 is a line diagram illustrating the fact that the sear remainsY locked when the tool is pressed against the work surface in a positionilnclined to the work surface.

Fig. 3 is a fragmentary longitudinal section showing the sear unlocked bythepressure ofthe tool against the work; surface aI position Substantielly perpendicular thereto.

Figure 4 is a fragmentary sectional view' ci a. modioation.,

The illustrative tool shown in thedrawins cem-I priSeS, a barrel I provided with a Chamber 2: adapted to receive a cartridge which is provided with a projectile in the form ci a: stud or otl'lerA elementl to be driven into or against the work. The chamber is closed by abreech bloc-h 31 which is apertured to provide for the movement: of a iiringl pin 4 to engage the cartridge primer; Breech block 3 is securedin a. frame which houses the ring mechanism andv is extended intoIv a handlev orv grip 6'. The ring' pin 4 is.` provided with a Sear-.engaging enlargement l and' is. urged forwardly by a firing spring il. Goeperatingwith the scar-engagingpartv 'E is a sear 9 pivotecl in the frame at to, and provided with a` head II adapted for displacement to release the firing pin by cam engagement with a trigger I2. which is mounted for rectilinear movement inV the frameand is provided with afinger piece. I3 within the gripr Si. Normally the sear is locked against firing pin releasing movement by a sear lock [4i which underlies the firing pin engaging portion a of the Sear and is mounted for rectilinear movement. in the frame., being thrust forward to its effective or scar-locking position by a spring t5 (Fig. 1),.

The barrel is held a housing I6 provided with an end plate I1 to which the barrel is secured, said end plate being rotatably secured to the breech block 3 by means of the pivot stud I8.

Sl idab1ymounted Qn the barrel I; within the'housing` I-B is an actiontube I9 to which is securedv an action bar '2U-that extends rearwardly-in alignment with and isfV adaptedl to displace the sea-c loclg III,i to permitring. Secured tothe forward end-ofA the action tube t9 and extending forwardly therefrom through housing I6 is an action tube extension 21;. A -springfZZ interposedbetween the rear end' of the action tube extension 2l' andy a shoulder on the barrel normally holds the actiontube assembly If-zIl-ZI inthe forward position illustrated in Fig. if.

The tool as thus far describedv is substantially' identical with the one shown in the aforementioned application of Walker, and' isdesigned partieularly for driving studs into diieultly penetrable materialsJ such as cinder block, cement block, Portland cement concrete, and steel. The impact of the stud, against aggregate materials of the concrete type tends to dislodge and forcefully expel small fragments or chips at the surface. To preventV damage and injury by suchflying particles, it is desirable to provide a shield which must be iirmlypressed against surface of thev wal-l,v floor,l beam or other structural member or fixture which is to be penetrated by the driven stud. For convenience, inI this specification and the claim appended thereto,r any member to which the tool is applied for the purpose of securingl a studtherein will, in accordance with wellestablished practice, be'referred to as the worki Since the work is usually a hard and difficultly penetrable material it becomes important to insure that the toolbe so applied to the work surfacev thatthe stud is driven in a direction substantiallyperpendicular to said surface, ratherl than oblique thereto. The present invention preyides not only-that the toolniust be held against the worlq,VA but thatit must be held essentially per@ pendicularto the wor-k surface to enable firing movement of the sear.

To thisy end,l two assemblies are provided, one an action tube assembly'orffaction member comY prise-ing action rbar 210, action tube I9 and action tube extension 2t;- and the other a guard assenh` bly slidably mounted on the reduced portion 2II o f action tube extension 2-I and comprising guard 25v havingl a eollar 2-4 xed to the` sleeve 23. Within the conical body' of' guard 25' and termihatingv in a f aee substantially perpendicular to the axis of the action tube and the barrel is a body 26 of a yieldably resilienty material"v such asv rubbeijfoij NEOP-RENE. The sleeve 23 of the guard assembly terminates a shoulder 231 which is wider than the shoulder 212 and is thus adapted for engagement with the end face I5=t et housing I'B (Fig. 3). 'The action tube assembly corrnoris`-` ing ports t9, 20 and 2l) beingfextended, the guard assembly (comprising ports 23, 24 and 25) thus has a movement upon action tube extension 2| equal to the difference between the length of the sleeve 23 and the spacing between collar 2I3 and shoulder 2 I2.

It will be remembered that the purpose of the tool is to re a cartridge which is placed in chamber 2, thereby driving a projectile into a surface which is engaged by the guard 25; that projectile firing is effected by movement of the firing pin 4 which is held in cocked position against the compression of spring 8 by sear 9; that firing pin releasing movement of said sear 9 is normally blocked by sear loci; I4; and that sear lock I4 is displaced to permit movement of sear 9 by action bar 2|). The mechanism constituting the present invention is designed to insure that the sear lock Hl is not displaced to permit firing unless the tool is held substantially perpendicular to the work face, as illustrated in Fig. 3. The end of action bar 20 is normally some distance away from the sear lock, as seen in Fig. l. If the tool is held oblique to the work face, in some such position as illustrated in Fig. 2, the rearward movement of action bar 20 is inadequate to engage and displace the sear lock, as clearly illustrated in Fig. 2. This is by reason of the fact that the action member (which comprises action tube I3, action bar 2|] and action tube extension 2|, all rigidly secured together and moving as a unit), has not performed it full rearward movement with respect to the barrel,

Fig. 1 shows the guard assembly in an intermediate position on the action tube extension 2|, on which it floats between shoulders 2I2 and 2I3, the action member, including the action tube extension, being thrust forwardly with respect to the barrel by spring 22. If the tool is presented obliquely to a work surface, a portion of the rim of guard 25 engages such work surface, thrusting the guard rearwardly on the action tube extension until the guard shoulder 23| engages the action tube extension shoulder 2 I2. Thereafter, guard and action tube extension move rearwardly with respect to the barrel until the guard shoulder 23| engages the forward end ISI of barrel housing I6, as shown in Fig. 2, stopping further rearward movement. The action member, being thrust forwardly on-the barrel by spring 22 and the guard being pushed to the rearward limit of its movement on the action member, the action member protrudes from the work engaging face of the guard, and action bar 2) has not engaged Sear lool: Ill. In this non-functioning position, it is obvious that the tool cannot be fired. If now the tool, being continuously thrust toward the work surface, is swung into a position substantially perpendicular to the work surface, as shown in Fig. 3, the guard assembly (comprising ports 23, .'i and 25) remains in the same position with respect to the barrel and its housing, due to the engagement of guard shoulder 23| with barrel housing shoulder I6I, but the action member (comprising ports I9, 23 and 2|) moves rearwardly with respect to both barrel and guard and in this movement the end of action bar 20 engages and displaces sear lock I4, as clearly shown at the right end of Fig. 3, thus enabling the tool to be fired. Any desired variation from the perpendicular within which ring can be done may be provided merely by varying the over-all length of the action tube assembly.

Fig. i shows a modified construction in which the guard collar 21| is floated directly upon the action tube extension 2|. A stud 3|) projecting outwardly from the action tube is received in a counterbore 3| in a sleeve member 32, which is secured to the guard collar 24 and oats on the action tube extension 2 I. The action tube extension 2| being forward, motion of the guard assembly thereon is limited by the engagement of stud 3l) with the end of collar 24 and the end 32| of counterbore 3 I. When the tool is pressed against a work surface, the rearward movement of the guard assembly (comprising ports 25 and 32) is limited by the engagement of the end 322 of sleeve 32 with the end IBI of housing I6 or a ring 33 of a buffer material such as NEOPRENE placed thereon. The construction of this modification is otherwise identical with that shown in Fig. 1; particularly in that within the housing I6, action tube extension 2| is joined to an action tube I9 which in turn is connected to action bar 20. Only when action bar 2|) is fully displaced to the rear can it engage and displace sear lock I4, to permit iiring; and this occurs only when the guard is against the frame I5, and the end of the action tube extension is flush with the guard face. If the tool is thrust obliquely against the work surface, only a small portion of the rim of guard 25 engages such surface and, due to this engagement, the guard is thrust rearward until shoulder 322 thereon engages the end I6I of the housing I 6, preventing further rearward movement of guard and action assembly. In this nonfunctioning condition, the forward end of action tube extension 2| protrudes from the work engaging face of the guard and the sear remains locked. As the tool is swung to a position perpendicular to the work face the action tube extension is moved rearwardly within the guard and the barrel housing until its free end is substantially flush with the work engaging face of the guard, thereby unlocking the action. This and other modifications are within the purview of the invention and the scope of the appended claim.

What is claimed is:

In a powder actuated tool adapted to drive a fastener into relatively Xed work, a barrel assembly comprising a barrel housing and a barrel having a rearward breech end housed in said housing, extending forwardly through and projecting from said housing and terminating in a muzzle plane perpendicular to the axis of said barrel; a frame assembly joined to said barrel assembly and comprising a firing device, a sear for controlling said firing device and a lock for said sear; a unitary action assembly comprising a tubular member mounted for longitudinal movement on said barrel from a forward normal position in which its forward end is in front of said muzzle plane to a rearward fully displaced position in which its forward end is substantially at said muzzle plane; a guard assembly mounted for limited movement on said tubular member and comprising a work-engaging face substantially perpendicular to the axis of said barrel, said guard assembly comprising motion limiting means adapted to engage said frame when the work-engaging face of the guard assembly is in the muzzle plane; said action assembly further comprising an action bar adapted to engage and displace said sear lock as said action assembly approaches its fully displaced position and the work-engaging face of the guard assembly is in the muzzle plane.

ROBERT T, CATLIN.

No references cited.

SIZ. 

